The invention provides a split pole-changing variable-speed outer rotor asynchronous motor and relates to a motor. The split pole-changing variable-speed outer rotor asynchronous motor comprises a stator component and a rotor component. By changing a connection type of a working winding coil in a working winding circuit and changing the connection type of a starting winding coil in a starting winding circuit at the same time, the quantity of stator magnetic poles of the motor is adjusted, pole changing and speed changing of the motor are realized, and the demand of a blower-pump load on a low-cost small-type motor energy saving technology is met. When the motor operates at a low speed gear, a silicon controlled chopping speed regulation method is adopted for lowering the terminal voltage of the motor, compared with the technical scheme that a common outer rotor asynchronous motor adopts the silicon controlled chopping speed regulation method for obtaining the same low rotational speed, the reduction extent of the terminal voltage of the motor is relatively small, waveform distortion of silicon controlled alternating current voltage is relatively small, electromagnetic noise of the motor during operation at a low rotational speed can be effectively inhibited, the copper loss of the motor is reduced, and the motor efficiency is improved.